<VV> Self pity and whining

[Tony Underwood]

At 05:18 hours 05/04/2006, Norman C. Witte wrote:
>Tony, I keep thinking vapor lock is a possibility.  The temp gauge on the
>dash shows that this motor seems to run a bit hot--maybe 425ish once its
>warmed up.  This morning I shot some starter fluid in the air cleaner,
>cranked it and it fired up no problem.  I'm not sure about gas formulation
>being the problem, since it was doing the same thing last fall, though I
>suppose that they may have changed over, as late as I was driving the car.


Gas doesn't seem to be as tolerant of things like this 
anymore.   Vapor lock generally (in my experience) hadn't really been 
a problem until the last few years or so.   The '69 Monza first did 
it when on a nice warm May day (humm) I went to the bank, parked on 
the street outside and noted that the pavement was really radiating 
as I crossed the street to do my banking.   Came back out after 
having stood in line for about ten minutes, got in the cart and made 
it a block when it gagged to a stop.    I thought that maybe the 
gauge was lying since it showed 1/4 tank, after I'd checked the carbs 
for a pump shot, nothing.    I then broke out the fan belt wrench 
(1/2x9/16 combo box end) and unbolted the fuel pump and "hand pumped" 
a while, nothing.   Usually you can hear fuel squishing through the 
pump but again, diddly.   I grabbed up the small vise grips in the 
glove box and *Carefully* detached a carb fuel line and tried pumping 
again, diddly.

I still couldn't believe it was vapor lock.  Off I went, gallon gas 
can in hand, to get more gas.    After fueling the car, I went back 
and began hand-pumping again.   I knew there was fuel in the tank 
now, and did note that the 1/4 tank level had risen after the fuel in 
the can was added... made me start thinking that there had been fuel 
in the tank the whole time.

Bad pump?   It was only a year old and was a *good* pump, no bogus 
item as had been defined several times in this forum.

I disconnected the fuel inlet line to the pump, and noted that when 
manually pumped the inlet made suction.

I was starting to get pissed.    It was hot, sun beating down, and my 
daughter was with me and having not very much fun.    In frustration 
I bent the fuel line upward a bit, bent over and stuck it in my mouth 
and blew on it.   Then I blew into it again until I was almost blue 
in the face, whereupon I finally was able to move air through the 
line, even heard bubbles gurgle in the tank.


Oddly enough, when I tried sucking on the fuel line (NO smart 
remarks) I was easily able to suck a mouthful of gas, sputtering and 
spitting etc.


All I could figure was that the underside of the car was hot, as was 
the fuel line, boiled fuel so that vapor was all that was there, and 
when I blew the fuel out of the line it was then replaced with cooler 
fuel in the tank, which cooled off the fuel lines and no more vapor lock.

Or something.

In any event, after I hand pumped the carbs full again, I secured the 
pump and the car started immediately.

Two weeks ago, same scenario with the '62 ragtop, stopped for a few 
minutes in a hot parking lot, then drove a block or two and 
pffft.   Initial checks showed no pump shot, acted like it was out of 
fuel.  This time we had somewhere to be at a set time so, since we 
were only a block or so away from the appointment, we just pushed the 
car into a parking lot with shade and left the car there over cool 
pavement, came back an hour later, cranked it a bit and it started 
right up.    No more issues.

Vapor lock.


>I suspected a contaminated fuel tank, but it only happens when the car has
>fully warmed up and then been parked for a short period of time.  When it
>finally starts, it starts like it never had a problem.  If it was a
>contamination problem, I don't think the timing would be so predictable.


Nope.   I'm convinced that gasoline today is just not what it used to 
be.  It's excessively volatile, boils easily, and even evaporates out 
of carbs easier than it used to as witness the thread a while back 
about people parking a Vair for a couple weeks and then it won't 
start without 30 seconds worth of cranking.



>Oh, and I should describe the symptoms when it dies.  Usually, it will start
>ok, run for a short distance, and then just kind of sputter and die.


Yep.  Classic vapor lock.


>Pumping or flooring the accelerator has no effect.  This makes me think that
>I am able to burn the fuel in the carb bowl and when that's gone it just
>starves.  Once this happens it will give a sputter or two, but that's it.


Ditto.



>But if it is vapor lock, what can I do to avoid this, short of getting an
>electric fuel pump somewhere forward of the engine compartment?  It's not a
>tolerable condition.


Nope, it sure isn't, especially when you're on the way to a rather 
important appointment and the car gags out two blocks away after a 
short stop parked on hot pavement.   .

Modern cars don't have to worry about vapor lock since the electric 
pumps (usually trunk-mounted) simply push the vapor bubbles down the 
line where they "burp" out.   Engine mounted fuel pumps don't have 
this advantage...

I'd maybe consider some fuel treatment products which have additives 
designed to combat vapor lock... or, add an electric pump at the tank 
to supplement the engine pump.   If you don't wanna deal with the 
safety issues of a full-time trunk-mounted electric fuel pump on a 
Vair, wire it to a push button switch so you can run it on demand via 
the push button, rather than have it run constantly; some people 
aren't real thrilled with an electric pump at the tank running 
full-time in a Vair, pressurizing the fuel lines from tank to engine 
etc.  since in most instances you're gonna have to use rubber hoses 
to couple things together whereas modern cars have steel lines from 
tank to injector, no rubber anywhere.

The part-time pump, especially the vibrator type, will serve 
nicely.  If you vapor lock, push the button.  The pump will chatter 
until it builds pressure and then it subsides and eventually 
stops.  You then know the carbs are full again, start up and off you 
go with the engine pump serving its intended purpose since the 
electric diaphragm pumps will freely flow fuel through them without 
their running.


The part-time electric pump also helps refill the carbs after the car 
sits for a week or two, fuel evaporating out of the carbs and you 
grind the starter until you pump them full again etc.


tony..